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CX2SA > SATDIG 28.03.18 03:56l 888 Lines 31919 Bytes #999 (0) @ WW
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From: CX2SA@CX2SA.SAL.URY.SOAM
To : SATDIG@WW
Today's Topics:
1. AO-92 fading (Jean Marc Momple)
2. Re: AO-92 fading (Paul Stoetzer)
3. Re: AO-92 fading (Burns Fisher)
4. Re: another rotator question (Rolf Krogstad)
5. Acquisition of equipment (Max)
6. Re: Acquisition of equipment (B J)
7. Re: Acquisition of equipment (Sterling Coffey)
8. Re: AO-92 fading (Stefan Wagener)
9. Re: Acquisition of equipment (Ted Krempa)
10. Re: AO-92 fading (Sterling Coffey)
11. Re: AO-92 fading (Stefan Wagener)
----------------------------------------------------------------------
Message: 1
Date: Tue, 27 Mar 2018 21:59:28 +0400
From: Jean Marc Momple <jean.marc.momple@?????.???>
To: amsat-bb <amsat-bb@?????.???>
Subject: [amsat-bb] AO-92 fading
Message-ID: <6037C742-149D-4964-B2AD-F159F0BD3780@?????.???>
Content-Type: text/plain; charset=us-ascii
Dear All,
I have been experimenting with AO-92 as from its launch. Some observations:
1) The fading on this bird seems to be high and quite unpredictable,
requires a lot of changes of polarization to keep the Rx signal to an
adequate level.
2) Seems that the fading is both on the U/V and L-mode, more seems to me
that the uplink is more affected.
3) Telemetry seems to be quite reliable with FoxTelem in all modes.
Today, it was even worse losing the bird many times during the pass, it
seems that it is degrading quite quickly, hope that this is not the case.
Just to share my observation.
73
Jean Marc (3B8du)
------------------------------
Message: 2
Date: Tue, 27 Mar 2018 14:12:59 -0400
From: Paul Stoetzer <n8hm@????.???>
To: Jean Marc Momple <jean.marc.momple@?????.???>
Cc: amsat-bb <amsat-bb@?????.???>
Subject: Re: [amsat-bb] AO-92 fading
Message-ID:
<CABzOSOq0FHazVBt1gAeDeLnNq9unMi_Aob_VMzhVjo_sqGAHMg@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
All of the Fox-1 satellites seem to spin faster or slower depending on
orbit illumination or other factors.
For example, this is the +Z panel rotation on AO-92 since launch.
https://imgur.com/a/uS8TB
Someone more well-versed in these matters can comment further on what
causes this, but it is definitely not an indication of the health
status of the satellite.
73,
Paul, N8HM
On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple
<jean.marc.momple@?????.???> wrote:
> Dear All,
>
> I have been experimenting with AO-92 as from its launch. Some observations:
>
> 1) The fading on this bird seems to be high and quite unpredictable,
requires a lot of changes of polarization to keep the Rx signal to an
adequate level.
>
> 2) Seems that the fading is both on the U/V and L-mode, more seems to me
that the uplink is more affected.
>
> 3) Telemetry seems to be quite reliable with FoxTelem in all modes.
>
> Today, it was even worse losing the bird many times during the pass, it
seems that it is degrading quite quickly, hope that this is not the case.
>
> Just to share my observation.
>
> 73
>
>
> Jean Marc (3B8du)
>
>
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
expressed
> are solely those of the author, and do not reflect the official views of
AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 3
Date: Tue, 27 Mar 2018 15:26:16 -0400
From: Burns Fisher <burns@??????.??>
To: Paul Stoetzer <n8hm@????.???>
Cc: amsat-bb <amsat-bb@?????.???>
Subject: Re: [amsat-bb] AO-92 fading
Message-ID:
<CABX7KxVCnPZ1oRi9wX5j1oWA8A5Sp2GTa49pVzuhbqwx=3F2Bg@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
If you have seen a model or picture of the Fox satellites, you may have
noticed that some of the solar panels seem to be mounted off-center. This
is intentional so that photons that reflect off the shiny side give it a
tiny off-center push that spins the bird to distribute the heat more
evenly. Thus it spins faster the more time it spends in the sun. In
addition, when it crosses the equator, it should flip over (-Z and +Z
reverse sides). This is because of the passive magnetic stabilization.
But I'm guessing that since it is spinning, that causes it to wobble.
Why 92 seems worse I don't know--I can only assume it has something to do
with the orbit. That graph that Paul posted looks very different from
AO-85, for example.
Some RF person can correct me, but I believe that the 70cm antenna only
uses the antenna that sticks out one side, while the 2m antenna actually
uses the antennas on both sides. Could that explain why the uplink has
more fading than the downlink? I don't know. Something to think about.
73,
Burns WB1FJ
Fox-1 Flight Software
On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer <n8hm@????.???> wrote:
> All of the Fox-1 satellites seem to spin faster or slower depending on
> orbit illumination or other factors.
>
> For example, this is the +Z panel rotation on AO-92 since launch.
>
> https://imgur.com/a/uS8TB
>
> Someone more well-versed in these matters can comment further on what
> causes this, but it is definitely not an indication of the health
> status of the satellite.
>
> 73,
>
> Paul, N8HM
>
> On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple
> <jean.marc.momple@?????.???> wrote:
> > Dear All,
> >
> > I have been experimenting with AO-92 as from its launch. Some
> observations:
> >
> > 1) The fading on this bird seems to be high and quite unpredictable,
> requires a lot of changes of polarization to keep the Rx signal to an
> adequate level.
> >
> > 2) Seems that the fading is both on the U/V and L-mode, more seems to me
> that the uplink is more affected.
> >
> > 3) Telemetry seems to be quite reliable with FoxTelem in all modes.
> >
> > Today, it was even worse losing the bird many times during the pass, it
> seems that it is degrading quite quickly, hope that this is not the case.
> >
> > Just to share my observation.
> >
> > 73
> >
> >
> > Jean Marc (3B8du)
> >
> >
> > _______________________________________________
> > Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> > to all interested persons worldwide without requiring membership.
> Opinions expressed
> > are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> > Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 4
Date: Tue, 27 Mar 2018 14:57:26 -0500
From: Rolf Krogstad <rolf.krogstad@?????.???>
To: "<AMSAT-BB@?????.???>" <amsat-bb@?????.???>
Subject: Re: [amsat-bb] another rotator question
Message-ID:
<CAJJyj=b-hzwdkAtpfCFO=NpC8GLT2W2ua20jFERuXCWN7k_FJA@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Problem resolved - without ascending the tower.
I had just purchased the PSTRotator software from Codrut YO3DMU to control
the rotators. It interfaces with the DDE interface from SDR-Console.which
I am using with my FunCube Dongle Pro Plus using the IdiomPress Yaesu DXA
CAT card and my Yaesu G-1000DXA rotator. It also interfaces with LVB
Tracker for my G-5400 elevation rotator.
So I asked Codrut and he suggested I try swapping pins 4 and 5. I had
tried swapping 1-2. 2-3, 1-3 with no luck.
I did that and recalibrated the LVB Tracker and I am now fully in business
with automated azimuth and elevation tracking of the satellites.
73
Rolf NR0T
On Tue, Mar 27, 2018 at 11:53 AM, Rolf Krogstad <rolf.krogstad@?????.???>
wrote:
> Question: My elevation rotator (Yaesu G-5400) works fine, but to raise
> the elevation I have to press the down button and to lower it, I press the
> Up button. How do I reverse this so it works as intended?
>
> Background:
> I had been the traditional HF ham for years. I had a tower with a TH7 and
> a Yaesu G-1000-DXA rotator. I then got into working satellites. I
> purchased a used Yaesu G-5400 rotator and controller. For the five years
> since installing the elevation rotator I have been manually controlling my
> rotators. I relabeled the up and down buttons on the controller and all
> was good. A few years ago I purchased a new LVB Tracker from AMSAT-NA but
> it sat on the shelf.
>
> I am now automating my rotators. I have the azimuth rotator working fine
> and have connected the LVB Tracker to control the elevation rotator and
> done the configuration routine. I can control the elevation using the LVB
> buttons, but must press up for down and down for up.
>
> I looked at the controller schematic and it appears that pins 1, 2, 3 of
> the rotator cable connector are connected to the potentiometer: pins 1 and
> 3 are on either end of the pot windings and pin 2 is the wiper.
>
> I set the antenna to 0 degrees elevation (0 on far left). I tried
> reversing the wires for 1 and 3, 1 and 2, 2 and 3. I don't think any of
> these will help me here, but am not sure.
>
> Any suggestions on how to reverse the buttons so that up is up and down is
> down?
>
> Thanks
>
> Rolf NR0T
> Grid EN34
>
------------------------------
Message: 5
Date: Tue, 27 Mar 2018 22:43:38 +0300
From: Max <max@????????.???.??>
To: amsat-bb@?????.???
Subject: [amsat-bb] Acquisition of equipment
Message-ID: <9547d0ba-a3b2-fb02-faea-35009ef4f510@????????.???.??>
Content-Type: text/plain; charset=utf-8; format=flowed
Good afternoon, I'm sorry that the question is not for you. Dear members
of the group, tell us where you can buy used equipment for work through
satellites. Thank you. 73 & GL.
------------------------------
Message: 6
Date: Tue, 27 Mar 2018 20:57:08 +0000
From: B J <va6bmj@?????.???>
To: Max <max@????????.???.??>
Cc: amsat-bb@?????.???
Subject: Re: [amsat-bb] Acquisition of equipment
Message-ID:
<CAP7QzkPyixW_nAYWtP-D8YZ4d_kEnjroJ2m0Jb0Fq6r7KCi9aQ@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
On 3/27/18, Max <max@????????.???.??> wrote:
> Good afternoon, I'm sorry that the question is not for you. Dear members
> of the group, tell us where you can buy used equipment for work through
> satellites. Thank you. 73 & GL.
<snip>
I bought my FT-847 and IC-910 through this site:
http://www.kwarc.org/swapshop/
73s
Bernhard VA6BMJ @ DO33FL
------------------------------
Message: 7
Date: Tue, 27 Mar 2018 15:59:33 -0500
From: Sterling Coffey <kawfey@?????.???>
To: B J <va6bmj@?????.???>
Cc: AMSAT <amsat-bb@?????.???>
Subject: Re: [amsat-bb] Acquisition of equipment
Message-ID:
<CACxCfFr5=G5q1ha_DEUEp2ddc=uZFqGWuXyFtN5ZxpH12=7eHA@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Additionally ebay, QRZ, eHam, craigslist, hamfests,
reddit.com/r/hamfest..all depends on what you need and what sats you want
to work.
On Tue, Mar 27, 2018 at 3:57 PM, B J <va6bmj@?????.???> wrote:
> On 3/27/18, Max <max@????????.???.??> wrote:
> > Good afternoon, I'm sorry that the question is not for you. Dear members
> > of the group, tell us where you can buy used equipment for work through
> > satellites. Thank you. 73 & GL.
>
> <snip>
>
> I bought my FT-847 and IC-910 through this site:
>
> http://www.kwarc.org/swapshop/
>
> 73s
>
> Bernhard VA6BMJ @ DO33FL
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 8
Date: Tue, 27 Mar 2018 19:22:37 -0500
From: Stefan Wagener <wageners@?????.???>
To: Burns Fisher <burns@??????.??>
Cc: amsat-bb <amsat-bb@?????.???>, Paul Stoetzer <n8hm@????.???>
Subject: Re: [amsat-bb] AO-92 fading
Message-ID:
<CAKu8kHAgbaN-EFQO3zEpf8Wre0TPH2EoCYs=Xtsrfw_ezJG3=A@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
One of the questions I have is why one would think that the uplink
(polarization) is a problem since you only have the downlink to assess and
how would you differentiate between uplink "weakness" from downlink since
that is the only thing you hear. In addition, at least for uplink, you
could "in principle" very quickly adjust with higher power... and no, I am
NOT promoting crocodile behavior (big mouth little ears)
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher <burns@??????.??> wrote:
> If you have seen a model or picture of the Fox satellites, you may have
> noticed that some of the solar panels seem to be mounted off-center. This
> is intentional so that photons that reflect off the shiny side give it a
> tiny off-center push that spins the bird to distribute the heat more
> evenly. Thus it spins faster the more time it spends in the sun. In
> addition, when it crosses the equator, it should flip over (-Z and +Z
> reverse sides). This is because of the passive magnetic stabilization.
> But I'm guessing that since it is spinning, that causes it to wobble.
>
> Why 92 seems worse I don't know--I can only assume it has something to do
> with the orbit. That graph that Paul posted looks very different from
> AO-85, for example.
>
> Some RF person can correct me, but I believe that the 70cm antenna only
> uses the antenna that sticks out one side, while the 2m antenna actually
> uses the antennas on both sides. Could that explain why the uplink has
> more fading than the downlink? I don't know. Something to think about.
>
> 73,
>
> Burns WB1FJ
> Fox-1 Flight Software
>
> On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer <n8hm@????.???> wrote:
>
> > All of the Fox-1 satellites seem to spin faster or slower depending on
> > orbit illumination or other factors.
> >
> > For example, this is the +Z panel rotation on AO-92 since launch.
> >
> > https://imgur.com/a/uS8TB
> >
> > Someone more well-versed in these matters can comment further on what
> > causes this, but it is definitely not an indication of the health
> > status of the satellite.
> >
> > 73,
> >
> > Paul, N8HM
> >
> > On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple
> > <jean.marc.momple@?????.???> wrote:
> > > Dear All,
> > >
> > > I have been experimenting with AO-92 as from its launch. Some
> > observations:
> > >
> > > 1) The fading on this bird seems to be high and quite unpredictable,
> > requires a lot of changes of polarization to keep the Rx signal to an
> > adequate level.
> > >
> > > 2) Seems that the fading is both on the U/V and L-mode, more seems to
> me
> > that the uplink is more affected.
> > >
> > > 3) Telemetry seems to be quite reliable with FoxTelem in all modes.
> > >
> > > Today, it was even worse losing the bird many times during the pass, it
> > seems that it is degrading quite quickly, hope that this is not the case.
> > >
> > > Just to share my observation.
> > >
> > > 73
> > >
> > >
> > > Jean Marc (3B8du)
> > >
> > >
> > > _______________________________________________
> > > Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> > > to all interested persons worldwide without requiring membership.
> > Opinions expressed
> > > are solely those of the author, and do not reflect the official views
> of
> > AMSAT-NA.
> > > Not an AMSAT-NA member? Join now to support the amateur satellite
> > program!
> > > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> > _______________________________________________
> > Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> > to all interested persons worldwide without requiring membership.
> Opinions
> > expressed
> > are solely those of the author, and do not reflect the official views of
> > AMSAT-NA.
> > Not an AMSAT-NA member? Join now to support the amateur satellite
> program!
> > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
> >
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
------------------------------
Message: 9
Date: Tue, 27 Mar 2018 17:27:06 -0700
From: "Ted Krempa" <k7trkradio@???????.???>
To: "'Sterling Coffey'" <kawfey@?????.???>, "'B J'" <va6bmj@?????.???>
Cc: 'AMSAT' <amsat-bb@?????.???>
Subject: Re: [amsat-bb] Acquisition of equipment
Message-ID: <001001d3c62b$80f48c00$82dda400$@???????.???>
Content-Type: text/plain; charset="US-ASCII"
...and, of course, there is EBay...which some here love or hate, but which
is the ONLY site that will give you buyer protection from scammers, parts
pickers or just outright thieves. The times that I have had to use EBay's
'buyer protection' has been 100% effective ! THAT is a fact..
Now, start the EBay bashing net..
73, Ted
K7TRK
-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces@?????.???? On Behalf Of Sterling
Coffey
Sent: Tuesday, March 27, 2018 2:00 PM
To: B J
Cc: AMSAT
Subject: Re: [amsat-bb] Acquisition of equipment
Additionally ebay, QRZ, eHam, craigslist, hamfests,
reddit.com/r/hamfest..all depends on what you need and what sats you want to
work.
On Tue, Mar 27, 2018 at 3:57 PM, B J <va6bmj@?????.???> wrote:
> On 3/27/18, Max <max@????????.???.??> wrote:
> > Good afternoon, I'm sorry that the question is not for you. Dear
> > members of the group, tell us where you can buy used equipment for
> > work through satellites. Thank you. 73 & GL.
>
> <snip>
>
> I bought my FT-847 and IC-910 through this site:
>
> http://www.kwarc.org/swapshop/
>
> 73s
>
> Bernhard VA6BMJ @ DO33FL
> _______________________________________________
> Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership.
> Opinions expressed are solely those of the author, and do not reflect
> the official views of AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
>
_______________________________________________
Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available to all
interested persons worldwide without requiring membership. Opinions
expressed are solely those of the author, and do not reflect the official
views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 10
Date: Tue, 27 Mar 2018 20:38:12 -0500
From: Sterling Coffey <kawfey@?????.???>
To: Stefan Wagener <wageners@?????.???>
Cc: Paul Stoetzer <n8hm@????.???>, amsat-bb <amsat-bb@?????.???>,
Burns Fisher <burns@??????.??>
Subject: Re: [amsat-bb] AO-92 fading
Message-ID:
<CACxCfFrWJ-_PqNatyC+GewaKDWJbXMd1p1a5jfM0dnUW5WV8Fg@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
You can hear your own signal if you have a full duplex (two radio) setup.
However, it's still pretty hard to tell if you use a single antenna (arrow,
elk, etc) since you're changing the RX polarity while you're changing the
TX polarity too.
On Tue, Mar 27, 2018 at 7:22 PM, Stefan Wagener <wageners@?????.???> wrote:
> One of the questions I have is why one would think that the uplink
> (polarization) is a problem since you only have the downlink to assess and
> how would you differentiate between uplink "weakness" from downlink since
> that is the only thing you hear. In addition, at least for uplink, you
> could "in principle" very quickly adjust with higher power... and no, I am
> NOT promoting crocodile behavior (big mouth little ears)
>
> Stefan, VE4NSA
>
> On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher <burns@??????.??> wrote:
>
> > If you have seen a model or picture of the Fox satellites, you may have
> > noticed that some of the solar panels seem to be mounted off-center.
> This
> > is intentional so that photons that reflect off the shiny side give it a
> > tiny off-center push that spins the bird to distribute the heat more
> > evenly. Thus it spins faster the more time it spends in the sun. In
> > addition, when it crosses the equator, it should flip over (-Z and +Z
> > reverse sides). This is because of the passive magnetic stabilization.
> > But I'm guessing that since it is spinning, that causes it to wobble.
> >
> > Why 92 seems worse I don't know--I can only assume it has something to do
> > with the orbit. That graph that Paul posted looks very different from
> > AO-85, for example.
> >
> > Some RF person can correct me, but I believe that the 70cm antenna only
> > uses the antenna that sticks out one side, while the 2m antenna actually
> > uses the antennas on both sides. Could that explain why the uplink has
> > more fading than the downlink? I don't know. Something to think about.
> >
> > 73,
> >
> > Burns WB1FJ
> > Fox-1 Flight Software
> >
> > On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer <n8hm@????.???> wrote:
> >
> > > All of the Fox-1 satellites seem to spin faster or slower depending on
> > > orbit illumination or other factors.
> > >
> > > For example, this is the +Z panel rotation on AO-92 since launch.
> > >
> > > https://imgur.com/a/uS8TB
> > >
> > > Someone more well-versed in these matters can comment further on what
> > > causes this, but it is definitely not an indication of the health
> > > status of the satellite.
> > >
> > > 73,
> > >
> > > Paul, N8HM
> > >
> > > On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple
> > > <jean.marc.momple@?????.???> wrote:
> > > > Dear All,
> > > >
> > > > I have been experimenting with AO-92 as from its launch. Some
> > > observations:
> > > >
> > > > 1) The fading on this bird seems to be high and quite unpredictable,
> > > requires a lot of changes of polarization to keep the Rx signal to an
> > > adequate level.
> > > >
> > > > 2) Seems that the fading is both on the U/V and L-mode, more seems to
> > me
> > > that the uplink is more affected.
> > > >
> > > > 3) Telemetry seems to be quite reliable with FoxTelem in all modes.
> > > >
> > > > Today, it was even worse losing the bird many times during the pass,
> it
> > > seems that it is degrading quite quickly, hope that this is not the
> case.
> > > >
> > > > Just to share my observation.
> > > >
> > > > 73
> > > >
> > > >
> > > > Jean Marc (3B8du)
> > > >
> > > >
> > > > _______________________________________________
> > > > Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum
> available
> > > > to all interested persons worldwide without requiring membership.
> > > Opinions expressed
> > > > are solely those of the author, and do not reflect the official views
> > of
> > > AMSAT-NA.
> > > > Not an AMSAT-NA member? Join now to support the amateur satellite
> > > program!
> > > > Subscription settings: http://www.amsat.org/mailman/
> listinfo/amsat-bb
> > > _______________________________________________
> > > Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
> > > to all interested persons worldwide without requiring membership.
> > Opinions
> > > expressed
> > > are solely those of the author, and do not reflect the official views
> of
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Message: 11
Date: Tue, 27 Mar 2018 20:44:15 -0500
From: Stefan Wagener <wageners@?????.???>
To: Sterling Coffey <kawfey@?????.???>
Cc: Paul Stoetzer <n8hm@????.???>, amsat-bb <amsat-bb@?????.???>,
Burns Fisher <burns@??????.??>
Subject: Re: [amsat-bb] AO-92 fading
Message-ID:
<CAKu8kHC4vJY7sSvJs2Gi=5AeVi21zc95D4JZ8Nza0Gq+=HBWWQ@????.?????.???>
Content-Type: text/plain; charset="UTF-8"
Thanks,
Again, even in full duplex how do you distinguish between a non-matching
uplink vs non-matching downlink? You only "hear" the downlink!
73, Stefan VE4NSA
On Tue, Mar 27, 2018 at 8:38 PM, Sterling Coffey <kawfey@?????.???> wrote:
> You can hear your own signal if you have a full duplex (two radio) setup.
> However, it's still pretty hard to tell if you use a single antenna (arrow,
> elk, etc) since you're changing the RX polarity while you're changing the
> TX polarity too.
>
> On Tue, Mar 27, 2018 at 7:22 PM, Stefan Wagener <wageners@?????.???>
> wrote:
>
>> One of the questions I have is why one would think that the uplink
>> (polarization) is a problem since you only have the downlink to assess and
>> how would you differentiate between uplink "weakness" from downlink since
>> that is the only thing you hear. In addition, at least for uplink, you
>> could "in principle" very quickly adjust with higher power... and no, I am
>> NOT promoting crocodile behavior (big mouth little ears)
>>
>> Stefan, VE4NSA
>>
>> On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher <burns@??????.??> wrote:
>>
>> > If you have seen a model or picture of the Fox satellites, you may have
>> > noticed that some of the solar panels seem to be mounted off-center.
>> This
>> > is intentional so that photons that reflect off the shiny side give it a
>> > tiny off-center push that spins the bird to distribute the heat more
>> > evenly. Thus it spins faster the more time it spends in the sun. In
>> > addition, when it crosses the equator, it should flip over (-Z and +Z
>> > reverse sides). This is because of the passive magnetic stabilization.
>> > But I'm guessing that since it is spinning, that causes it to wobble.
>> >
>> > Why 92 seems worse I don't know--I can only assume it has something to
>> do
>> > with the orbit. That graph that Paul posted looks very different from
>> > AO-85, for example.
>> >
>> > Some RF person can correct me, but I believe that the 70cm antenna only
>> > uses the antenna that sticks out one side, while the 2m antenna actually
>> > uses the antennas on both sides. Could that explain why the uplink has
>> > more fading than the downlink? I don't know. Something to think about.
>> >
>> > 73,
>> >
>> > Burns WB1FJ
>> > Fox-1 Flight Software
>> >
>> > On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer <n8hm@????.???> wrote:
>> >
>> > > All of the Fox-1 satellites seem to spin faster or slower depending on
>> > > orbit illumination or other factors.
>> > >
>> > > For example, this is the +Z panel rotation on AO-92 since launch.
>> > >
>> > > https://imgur.com/a/uS8TB
>> > >
>> > > Someone more well-versed in these matters can comment further on what
>> > > causes this, but it is definitely not an indication of the health
>> > > status of the satellite.
>> > >
>> > > 73,
>> > >
>> > > Paul, N8HM
>> > >
>> > > On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple
>> > > <jean.marc.momple@?????.???> wrote:
>> > > > Dear All,
>> > > >
>> > > > I have been experimenting with AO-92 as from its launch. Some
>> > > observations:
>> > > >
>> > > > 1) The fading on this bird seems to be high and quite unpredictable,
>> > > requires a lot of changes of polarization to keep the Rx signal to an
>> > > adequate level.
>> > > >
>> > > > 2) Seems that the fading is both on the U/V and L-mode, more seems
>> to
>> > me
>> > > that the uplink is more affected.
>> > > >
>> > > > 3) Telemetry seems to be quite reliable with FoxTelem in all modes.
>> > > >
>> > > > Today, it was even worse losing the bird many times during the
>> pass, it
>> > > seems that it is degrading quite quickly, hope that this is not the
>> case.
>> > > >
>> > > > Just to share my observation.
>> > > >
>> > > > 73
>> > > >
>> > > >
>> > > > Jean Marc (3B8du)
>> > > >
>> > > >
>> > > > _______________________________________________
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>> available
>> > > > to all interested persons worldwide without requiring membership.
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>> > > > are solely those of the author, and do not reflect the official
>> views
>> > of
>> > > AMSAT-NA.
>> > > > Not an AMSAT-NA member? Join now to support the amateur satellite
>> > > program!
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>> istinfo/amsat-bb
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>> > > Sent via AMSAT-BB@?????.???. AMSAT-NA makes this open forum available
>> > > to all interested persons worldwide without requiring membership.
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>> > > expressed
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>> of
>> > > AMSAT-NA.
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>> > >
>> > _______________________________________________
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>> > to all interested persons worldwide without requiring membership.
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>> > expressed
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>> >
>> _______________________________________________
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>> to all interested persons worldwide without requiring membership.
>> Opinions expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
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>
>
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End of AMSAT-BB Digest, Vol 13, Issue 117
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